Pension transfer help

[shindha]

Sorry about the long post but here goes: For almost 20 years I have been self employed and for the first 15 years I paid into a private pension fund. However, I haven't paid anything into this for the last 5 years and I am now working for the NHS and have decided to pay into their pension scheme.

I have approximately 15 years before I reach retirement age and my questions are: Should I merge my private but paltry pension fund with my NHS pension fund? Is it a good time to buy into the NHS pension? Or are my interest best served if I leave my private pension fund to sit idle?
Thanks in advance.